Viability and susceptibility of propagation material from coffee plants to Colletotrichum sp.

Abstract

This study aimed to verify the viability of propagation material from coffee plants descended from germplasm susceptible to blister spot disease as well as its susceptibility to Colletotrichum sp. relative to commercial coffee cultivars. In the first experiment, fruits were harvested from plants with and without symptoms of blister spot and sowed in trays containing a commercial sterilized substrate. The percentages of germinated seeds, viable plantlets and seedlings were evaluated. In diseased tissues, pathogens were isolated and identified though a pathogenicity test. In the second experiment, ten commercial cultivars and one cultivar originating from plants with blister spot were inoculated with the pathogens to assess the severity of anthracnose. Significant differences were not observed with respect to seed germination. However, the viability of plantlets and seedlings was reduced in the cultivar originating from plants with blister spot (Genotype Originated from Diseased Plants-GODP). These plants showed characteristic symptoms of blister spot, including necrosis in the leaves and hypocotyls, wilting and death. In the necrotic lesions, we observed characteristic sporulation of Colletotrichum sp. The cultivar most susceptible to anthracnose in cotyledonary leaves was Catuaí Vermelho (GODP), which presented the highest area under the disease progress curve (AUDPC). In conclusion, the viability of propagation material from coffee plants that had descended from plants with symptoms of blister spot (GODP) was reduced compared with plants from other genotypes, although seed germination was not affected. Moreover, GODP species are more susceptible to Anthracnose on the cotyledonary leaves relative to the other analyzed commercial cultivars. This work is the first to report on different symptoms exhibited by seedlings originating from the seeds of plants with symptoms of blister spot.